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Diffusion Metamaterial
Diffusion metamaterials are a subset of the metamaterial family, which primarily comprises thermal metamaterials, particle diffusion metamaterials, and plasma diffusion metamaterials. Currently, thermal metamaterials play a pivotal role within the realm of diffusion metamaterials. The applications of diffusion metamaterials span various fields, including heat management, chemical sensing, and plasma control, offering capabilities that surpass those of traditional materials and devices. History In 1968, Veselago introduced the concept of negative refractive index. Subsequently, John Pendry recognized the potential of using artificial microstructures to achieve unconventional electromagnetic properties. He conducted pioneering research involving metal wire arrays and split ring structures. His groundbreaking contributions ignited a surge of interest in the field of electromagnetic or optical metamaterials. Researchers began to focus on manipulating transverse waves through metamate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamaterial
A metamaterial (from the Greek word μετά ''meta'', meaning "beyond" or "after", and the Latin word ''materia'', meaning "matter" or "material") is a type of material engineered to have a property, typically rarely observed in naturally occurring materials, that is derived not from the properties of the base materials but from their newly designed structures. Metamaterials are usually fashioned from multiple materials, such as metals and plastics, and are usually arranged in repeating patterns, at scales that are smaller than the wavelengths of the phenomena they influence. Their precise shape, geometry, size, orientation, and arrangement give them their "smart" properties of manipulating electromagnetic, acoustic, or even seismic waves: by blocking, absorbing, enhancing, or bending waves, to achieve benefits that go beyond what is possible with conventional materials. Appropriately designed metamaterials can affect waves of electromagnetic radiation or sound in a manner n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Pendry
Sir John Brian Pendry, (born 4 July 1943) is an English theoretical physicist known for his research into metamaterials and creation of the first practical "Invisibility, Invisibility Cloak". He is a professor of theoretical solid state physics at Imperial College London where he was head of the department of physics (1998–2001) and principal of the faculty of physical sciences (2001–2002). He is an honorary fellow of Downing College, Cambridge, (where he was an undergraduate) and an IEEE fellow. He received the Kavli Prize in Nanoscience "for transformative contributions to the field of nano-optics that have broken long-held beliefs about the limitations of the resolution limits of optical microscopy and imaging.", together with Stefan Hell, and Thomas Ebbesen, in 2014. Education Pendry was educated at Downing College, Cambridge, graduating with a Master of Arts degree in Natural Sciences (Cambridge), Natural Sciences and a PhD in 1969. Career John Pendry was born in Manch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitudinal Wave
Longitudinal waves are waves which oscillate in the direction which is parallel to the direction in which the wave travels and displacement of the medium is in the same (or opposite) direction of the wave propagation. Mechanical longitudinal waves are also called ''compressional'' or compression waves, because they produce compression and rarefaction when travelling through a medium, and pressure waves, because they produce increases and decreases in pressure. A wave along the length of a stretched Slinky toy, where the distance between coils increases and decreases, is a good visualization. Real-world examples include sound waves (vibrations in pressure, a particle of displacement, and particle velocity propagated in an elastic medium) and seismic P waves (created by earthquakes and explosions). The other main type of wave is the transverse wave, in which the displacements of the medium are at right angles to the direction of propagation. Transverse waves, for instance, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ji-Ping Huang
Ji-Ping Huang (alternative spelling forms: J. P. Huang or Jiping Huang; simplified Chinese: 黄吉平；born 8 January 1977) is a Chinese theoretical physicist known for his invention of the concept of diffusion metamaterials. Education Huang obtained a BSc and MSc from the Department of Physics at Soochow University, China, in 1998 and 2000, respectively. He earned his PhD from the Department of Physics at the Chinese University of Hong Kong, China, in 2003. Career Huang was a postdoctoral researcher at the Max Planck Institute for Polymer Research, Germany, from 2003 to 2004. He then held the position of a Humboldt Research Fellow at the same institute from 2004 to 2005. In 2005, he assumed the role of a professor in the Department of Physics at Fudan University, China. Research His research area encompasses thermodynamics, statistical physics, and complex systems, with a particular emphasis on transformation thermotics and its extended theories, thermal metamaterials a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Conduction
Thermal conduction is the diffusion of thermal energy (heat) within one material or between materials in contact. The higher temperature object has molecules with more kinetic energy; collisions between molecules distributes this kinetic energy until an object has the same kinetic energy throughout. Thermal conductivity, frequently represented by , is a property that relates the rate of heat loss per unit area of a material to its rate of change of temperature. Essentially, it is a value that accounts for any property of the material that could change the way it conducts heat. Heat spontaneously flows along a temperature gradient (i.e. from a hotter body to a colder body). For example, heat is conducted from the hotplate of an electric stove to the bottom of a saucepan in contact with it. In the absence of an opposing external driving energy source, within a body or between bodies, temperature differences decay over time, and thermal equilibrium is approached, temperature becom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Swarm Optimization
In computational science, particle swarm optimization (PSO) is a computational method that Mathematical optimization, optimizes a problem by iterative method, iteratively trying to improve a candidate solution with regard to a given measure of quality. It solves a problem by having a population of candidate solutions, here dubbed Point particle, particles, and moving these particles around in the Optimization (mathematics)#Concepts and notation, search-space according to simple formula, mathematical formulae over the particle's Position (vector), position and velocity. Each particle's movement is influenced by its local best known position, but is also guided toward the best known positions in the search-space, which are updated as better positions are found by other particles. This is expected to move the swarm toward the best solutions. PSO is originally attributed to James Kennedy (social psychologist), Kennedy, Russell C. Eberhart, Eberhart and Yuhui Shi, Shi and was first int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiative Cooling
In the study of heat transfer, radiative cooling is the process by which a body loses heat by thermal radiation. As Planck's law describes, every physical body spontaneously and continuously emits electromagnetic radiation. Radiative cooling has been applied in various contexts throughout human history, including Ice-making, ice making in India and Iran, Heat shield, heat shields for spacecraft, and in architecture. In 2014, a scientific breakthrough in the use of Photonic metamaterial, photonic metamaterials made daytime radiative cooling possible. It has since been proposed as a strategy to mitigate local and global warming caused by greenhouse gas emissions known as passive daytime radiative cooling. Terrestrial radiative cooling Mechanism Infrared radiation can pass through dry, clear air in the wavelength range of 8–13 μm. Materials that can absorb energy and radiate it in those wavelengths exhibit a strong cooling effect. Materials that can also reflect 95% or mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
